Guocheng Huang

Non-covalent interfacial interactions in covalent organic frameworks (COFs) enable precise regulation of directional charge migration under mild conditions with high reproducibility, yet their controllable construction remains challenging and the underlying interaction mechanism is still ambiguous. Herein, polydopamine (PDA) was linked onto a thiophene-based COF (BT-COF) via van der Waals forces and hydrogen bonding, constructing a metal-free composite photocatalytic system denoted as BT-COF/PDA. This non-covalent interfacial engineering establishes strong synergistic interfacial coupling between BT-COF and PDA, which not only broadens the light-response range and suppresses product decomposition, but also forms a well-defined charge-transfer pathway. Consequently, the representative BT‐COF/PDA50 achieved a high hydrogen peroxide (H2O2) production rate of 4548 μmol g-1 h-1 in air without any additional sacrificial agents, which is 3.11 times higher than that of pristine BT‐COF. Its apparent quantum yield (AQY) reached 5.38% at 420 nm, significantly surpassing those of conventional photocatalysts. Moreover, by coupling with exogenous Fe2+ to construct a photo‐Fenton system, efficient inactivation of Escherichia coli within 45 min was accomplished, demonstrating its synergistic photocatalytic disinfection capability. This work not only provides new insights into optimizing charge‐transfer dynamics through surface‐modification engineering, but also offers a promising strategy for efficient H2O2 synthesis and rapid aqueous‐phase disinfection.

The rational regulation of the electronic structure in single‐atom catalysts (SACs) is pivotal yet challenging for enhancing photocatalytic CO ₂ reduction. Herein, we elaborately designed a series of M ₁ N ₂ sites (M = Au, Pt, Pd, Ru, Mo) anchored on a vinylene‐linked covalent organic framework (sp ² c‐COF) to construct M/COF SACs for gas‐solid CO ₂ photoreduction. The M/COF SACs revealed a d‐orbital electronic configuration‐dependent activity, where the d‐band center exhibiting strong correlation with CO ₂ adsorption energy (R ² = 0.98). Notably, the Mo/COF catalysts delivered a superior CO rate of 294.43 µmol·g ⁻¹ ·h ⁻¹ with near‐unity selectivity under pure CO ₂ and sustained 146.6 µmol·g ⁻¹ ·h ⁻¹ under simulated flue gas (15% CO ₂ ). The superior activity originates from the synergistic interplay of its highest d‐band center (−0.314 eV) and strongest spin polarization among the series. This unique electronic structure, featuring abundant single‐atom states near the Fermi level and half‐occupied d orbitals, facilitates optimal σ‐donation (via d _z2 ) and π‐back‐donation (via d _xz /d _yz ) for CO ₂ activation, thereby significantly lowering the energy barriers for *COOH formation and *CO desorption. This work establishes a design principle for high‐performance SACs through the co‐modulation of d‐band configuration and spin polarization.

Covalent organic frameworks (COFs) have emerged as a platform for photocatalysis owing to their modular architectures and well‐defined porous frameworks. However, the low dielectric constants of organic frameworks lead to strong dielectric confinement and large exciton binding energies, which severely limit charge separation efficiency and photocatalytic performance. Herein, we report a viable strategy for modulating dielectric confinement via counteranion engineering. Halogen‐functionalized ionic COFs were fabricated by first synthesizing a highly conjugated EB‐COF:Br scaffold via Schiff base condensation between the ionic amino monomer ethidium bromide and the aldehyde linker 2,4,6‐triformylphloroglucinol, followed by ion exchange with F ⁻ , Cl ^‐, and I ⁻ . We found that the strategy can modulate photocatalytic H ₂ O ₂ production and bactericidal performance, which is attributed to variations in permittivity and exciton binding energy resulting from the differential polarization of ionic moieties. Notably, EB‐COF:Cl exhibits enhanced exciton dissociation efficiency and a remarkably elevated H ₂ O ₂ production (1400 μmol·g ⁻¹ ·h ⁻¹ ) when using seawater as the reaction medium, which is 1.65 times that of the pure water system. This work establishes a feasible strategy for regulating the dielectric confinement effect of iCOFs to enhance H ₂ O ₂ production, with the improved performance in seawater systems endowing the material with promising practical applicability for marine‐related environmental remediation.

A charge accumulation strategy in multicomponent covalent organic frameworks (COFs) is developed to maximize photocatalytic H ₂ O ₂ production. By precisely arranging building blocks into a D‐A‐A′‐A‐D configuration, photogenerated electrons from dual donors are funneled and confined at the high‐electron‐affinity A′ center. This spatial convergence creates a localized “electron reservoir” that significantly enhances oxygen adsorption and activation, thereby optimizing the oxygen reduction kinetics at the active sites. Consequently, the charge accumulation D‐A‐A′‐A‐D configured representative material COF‑2CN‑2 delivers a H ₂ O ₂ evolution rate of 6864.68 µmol·g ⁻¹ ·h ⁻¹ without sacrificial agents or external oxygen, with an apparent quantum yield (AQY) of 14.13% at 420 nm and a solar‑to‑chemical conversion (SCC) efficiency of 1.27%, which significantly surpasses those obtained with conventional structural arrangements. Notably, it maintains robust photocatalytic activity under natural sunlight in real water. This work offers novel insights into enhancing charge transport within multicomponent COFs and provides a rational design strategy for high‑performance photocatalysts.

A charge accumulation strategy in multicomponent covalent organic frameworks (COFs) is developed to maximize photocatalytic H ₂ O ₂ production. By precisely arranging building blocks into a D‐A‐A′‐A‐D configuration, photogenerated electrons from dual donors are funneled and confined at the high‐electron‐affinity A′ center. This spatial convergence creates a localized “electron reservoir” that significantly enhances oxygen adsorption and activation, thereby optimizing the oxygen reduction kinetics at the active sites. Consequently, the charge accumulation D‐A‐A′‐A‐D configured representative material COF‑2CN‑2 delivers a H ₂ O ₂ evolution rate of 6864.68 µmol·g ⁻¹ ·h ⁻¹ without sacrificial agents or external oxygen, with an apparent quantum yield (AQY) of 14.13% at 420 nm and a solar‑to‑chemical conversion (SCC) efficiency of 1.27%, which significantly surpasses those obtained with conventional structural arrangements. Notably, it maintains robust photocatalytic activity under natural sunlight in real water. This work offers novel insights into enhancing charge transport within multicomponent COFs and provides a rational design strategy for high‑performance photocatalysts.

Photocatalytic CO ₂ reduction offers a promising strategy to mitigate the greenhouse effect, yet it remains a challenging process due to the high energy barrier associated with the high stability of CO ₂ . In this study, we synthesized Py‐bTDC, a pyrene‐based covalent organic framework (COF) enriched with nitrogen and sulfur atoms, and anchored palladium nanoclusters (Pd NCs) onto its structure to enhance CO ₂ reduction efficiency. The confined Pd NCs amplify the built‐in electric field (IEF), enabling efficient photogenerated carrier migration and suppressing electron‐hole recombination. Simultaneously, Pd NCs serve as catalytic active sites, optimizing CO ₂ adsorption and activation. Density functional theory (DFT) calculations reveal that Pd reduces the energy barrier for forming the critical intermediate (*COOH), thereby accelerating CO production. Under visible‐light irradiation in a gas‐solid system using water as a proton donor, the Pd ₃ /Py‐bTDC composite achieved a CO evolution rate of 17.75 µmol·h ⁻¹ ·g ⁻¹ with 86.0% selectivity. This study advances the design of COF‐based photocatalysts by synergistically modulating IEF and the engineering active sites for efficient CO ₂ reduction.

The global need for clean water and sanitation drives the development of eco-friendly and efficient water treatment technologies to combat biological pollution from pathogens. In this study, a novel heterojunction photocatalyst was synthesized by incorporating ZnIn₂S₄ into covalent organic frameworks (COFs) to enable environmentally friendly hydrogen peroxide (H₂O₂) photosynthesis and explore its potential for in situ disinfection. The ZnIn₂S₄/COF photocatalyst achieved remarkable H₂O₂ yields of 1325 µmol∙g⁻¹∙h⁻¹, surpassing pristine COF and ZnIn₂S₄ by factors of 3.12 and 16.2, respectively. The produced H₂O₂ was efficiently activated into hydroxyl radicals (·OH) through reaction with Fe(II), enabling rapid sterilization via a photocatalysis-self-Fenton system. Mechanistic insights, supported by physicochemical characterizations and theoretical calculations, highlighted the role of the internal electric field (IEF) in enhancing carrier separation and transfer, thereby boosting photosynthesis efficiency. This work presents a sustainable approach to H₂O₂ photosynthesis and activation for disinfection, offering a promising solution to global water treatment challenges.